Apparatus for use in manufacturing artificial filaments



y 1941- w. OSTE RMANN 2,243,116 APPARATUS FOR USE IN MANUFACTURINGARTIFICIAL FIL'A'MEN'I'S Filed March 8, 1937 Patented May 27, 1941APIARATUS FOR USE IN MANUFACTURING ARTIFICIAL FILAMENTS WalterOstermann, Wuppertal-Barmen, Germany, assignor to American BembergCorporation, New York, N. Y., a corporation of Delaware ApplicationMarch 8, 1937, Serial N 0. 129,541 In Germany March 9, 1936 12 Claims.

The present invention relates to the manufacture of filaments ofartificial origin but more specifically has for its purpose to devise anovel method of and apparatus for the spinning of such filaments.

Ln the spinning of artificial filaments by the wet-spinning process aspinning solution is extruded through the openings of a spinnerettenozzle, which may be immersed in a precipitating medium, and thespinning solution, as it is extruded from the openings of thespinnerette, is precipitated by the medium or bath, and the thread orfilaments are thus formed.

In the Wet-spinning of artificial filaments, such, for example, as bythe cuprammonium process, spinnerettes having comparatively smallopenings are employed and the spinnerettes immersed in precipitatingbaths, such as sulphuric acid or caustic soda solutions, which quicklycoagulate the filaments as they are extruded in the said bath. In someinstances it is desirable to have these baths flow in a trough, which isapproximately horizontal, and from one end of the machine to the otherthe threads being drawn vertically from the bath. This method ofspinning does not result in uniform coagulation of the filaments fromspinning station to spinning station, due to the change in concentrationof the bath as it flows past the different spinning stations.

It is therefore one purpose of the present invention to provide anarrangement to overcome the aforementioned disadvantage by surroundingeach spinning nozzle with a funnel arrangement and providing nozzlesfrom which fresh precipitation liquid is supplied in the direction oftravel of the thread. A novel feature of the present invention consistsin a pipe-like insertion which is positioned in the precipitating bathtrough and concentrically around the thread, together with nozzles fromwhich fresh precipitating liquid is supplied in the direction of travelof the extruded thread.

The liquid stream ejecting from the nozzles and into the funnel deviceproduces a positive flow of the spinning bath therethrough. A continuousrenewal of the spin bath arotmd the spinnerette and at the point ofextrusion of the freshly spun thread results from the arrangement. Theflow of the spin bath in the direction of travel of the filaments aidsin the stretching and strengthening of the freshly extruded thread.

It is therefore one object of the present invention to provide uniformspinning conditions at all spinning stations of a spinning machine.

Another object of the present invention is to provide an arrangement andmethod whereby stretching or strengthening of the freshly extrudedthreads results.

Important features of the invention in its preferred form compriseproviding a continuous supply of fresh precipitating medium adjacent theextrusion nozzle and causing the precipitating medium to fiow in thedirection of travel of the freshly extruded threads.

Other objects will become apparent.

Referring to the drawing, Figure 1 shows a diagrammatic verticalcross-section of a spinning machine with one embodiment of the inventionopcratively positioned therein. Figure 2 is a view similar to Figure 1illustrating a modified form of the invention.

In the drawing in which like numerals of reference indicate like parts,I refers to the usual type of spinning pipe including a candle filterand having attached thereto a spinnerette 2. The spinning pipe I ispivotally mounted as indicated at la in the usual manner whereby it maybe swung into and out of the spin bath trough 3 and the liquid containedtherein.

The wall 4 of the spin bath trough 3 has attached thereto a spin bathsupply pipe 5. The spin bath enters the trough 3 through a plurality ofnozzles positioned annularly around the spinning nozzle 2, two of whichare illustrated at 6.

A funnel-like member I is positioned in the spin bath trough 3 andconcentric to the spinning nozzle 2. The precipitating liquid is forced,together with the thread 8, through the conical insertion tube 7 andinto the tapered portion 9 of the latter.

The thread 8 as it issues from the spinning nozzle is drawncentrallythrough the funnel l and around a guide roller H] which may be partiallysubmerged in the spin bath. This roller in the embodiment illustrated isfreely rotatable and driven by the thread drawn around it, but, ifdesired, it may be a positively driven roller. The thread is drawn fromthere to a suitable take-up device (not shown). The guide roller Ill ispreferably positioned adjacent the tapered end 9 of the funnel l.

The fresh spin bath coming from the nozzles 6 is forced to flow in thedirection of travel of the thread 8 by reason of the funnel I.

An overflow I6 is provided whereby the used spin bath may be carried offat the same rat at which it is supplied.

A flange H which may be formed integral to the outside of the funnel lis provided for the purpose of uniformly positioning the said funnel lin the supporting frames I2 and 13. Of course, other means may beprovided for accomplishing this purpose.

In operation the roller I is first moved into the position shown indotted lines in Figure 1. The funnel is lifted from the frames 12 and13. The spinnerette together with the spinning pipe I and spinnerette 2may be swung out of the trough, as shown in dotted lines, for cleaningor changing of the spinnerette. After the cleaning or changingoperation, the spinning pipe l and spinnerette 2 are swung back againinto the precipitating bath. The funnel 'l is placed in position on theframes I2 and I3, and surrounding the spinnerette 2 and the spinningoperation is then begun.

The thread bundle 8 is pulled through the mouth of the funnel by anysuitable means such as, for example, a hook. After the thread has beenpulled through the funnel I the roller i0 is moved into the position,shown in full lines, and at the same time the thread 8 is led to awinding device. After the roller H! has been placed in position, alocking pin 14 is positioned in place on a bracket l and holds the saidroller l0 in the spinning position.

In Figure 2 is illustrated a modified form of the invention. In thisinstance the spinnerette 2| which is mounted on a spinning pipe 2Ia. canbe swung into and out of spinning position on its pivot 2lb the same asdescribed with relation to Figure 1.

In this form of the invention, the spinnerette 2i discharges verticallyand the thread 30 is drawn therefrom in a vertical direction.

The funnel 23 which is positioned concentrically around the spinningnozzle has an annular enlargement 22 which rests on the circular bracket24 and is supported thereby. The bracket 24 is pivotally mounted at 25on the side of the spin bath trough 26.

The trough 26 has a closed chamber 2'! formed in the bottom thereof andto which the fresh spinning bath solution is fed under pressure througha pipe 3!. Nozzles 28 are positioned adjacent the spinning nozzle 21 andare the outlets through which the spin bath solution is forced from thechamber 21. These nozzles may consist of two or more nozzles arrangedconcentrically around the spinning nozzle.

By reason of this structure, a constant flow of fresh spinning solutionpasses upwardly past the spinning nozzle 2| and along the funnel 23,whereby a strong upward circulation of the spinning liquid is produced.

The spin bath then overflows the upper edge of the funnel 23 and intothe spinning trough 26, A portion of it overflows from the trough andthe remainder is circulated again upwardly through the funnel 23.

An overflow 29 is provided whereby the used spin bath liquid isdischarged at the same rate at which it is supplied.

To start the spinning operation, the funnellike insertion 23 is swungout of the bath on the pivot 25, The spinnerette 2| may then be swung onits pivot 2H) for the purpose of exchanging spinning nozzles and afterthe spinning solution begins to emerge the spinnerette is swung backinto the bath. The funnel 23 and its support 24 are swung on the pivot25 down to a point where the funnel may surround the spinning nozzle 2|.

The extruded thread bundle is then led to a winding device in any wellknown manner (not shown).

The form of the funnel insertion may be either substantially cylindricalor substantially conical. The effect on the freshly extruded threaddepends upon the conicity of the funnel, i. e., whether the diameter ofthe funnel decreases or increases in the direction of the travel of thethread.

If the diameter of the funnel decreases in the direction of travel ofthe thread, an acceleration of the flow of precipitating liquid in thisdirection takes place. This acceleration of the flow of the liquidexerts a stretching action on the thread in addition to that which wouldresult from the flow of liquid from the nozzles through a cylindricaltube. If, on the other hand, the diameter of the funnel becomes greaterin the direction of travel of the thread, the speed of the spinning bathwill gradually decrease. In this instance, the stretching of the threadtakes place owing to increased friction on the spinning bath liquid,which resists the drawing of the thread by the rotor or other drawingdevice. At the same time continuous removal of the bath in the vicinityof the spinning nozzle is maintained.

The funnel insertion, whether cylindrical or conical, may be positionedvarious distances from the spinnerette. It is advantageous to positionthe spinnerette either completely or partially within the funnel. If itis desired to maintain uniformly the direction of travel of thread inthe said funnel a thread guide may be provided at the mouth of thefunnel as shown at It in order to direct the passage of the thread tothe take-up device of the spinning machine, i. e., the spinning spool,an intermediate drawing roller or take-up godet, or to a centrifugalspinning pot or the like. I

The thread guide may be in the form of a roller which is eitherpositively driven or which rotates freely as the thread passes thereoverunder the drawing power ,of an additional device that draws .off thethread. However, a stationary guide may how of liquid where the threadcontacts the guide roller is of great advantage, due to a more perfectwashing or rinsing of the said thread guide.

The upwardly extending mouth 9 of the funnel I as shown in Figure 1 isalso effective in this respect. The upward inclination of the mouth 9causes the liquid stream ejected from the funnel to flow slightlyupwardly so that it is directed in the direction of the roller in whereit exercises its favorable rinsing action.

Under certain circumstances, it may be preferable to arrangeprecipitating bath nozzles in an intermediate bottom mounted in thetrough, as

shown in Figure 2 and to feed them from a precipitating bath room whichis held under a constant pressure.

As shown in both forms of the invention, a

certain annular space or clearance is left between the mouth of thefunnel and the sides of the spinning bath trough and arrangements may beprovided whereby this clearance may be varied. For example, asillustrated in Figure 2 of the drawing, the bracket 24 may be adjustablymounted to slide in a sleeve 32 and held in position in said sleeve by aset screw 33.

The force of the precipitating bath stream flowing through the funneldepends largely upon the size of the funnel and the flowing power of theprecipitating bath at the time when it emerges from the spin bathnozzles, and upon the size of the clearance existing between the end ofthe funnel facing the nozzle and the wall adjacent the nozzle. Asbrought out above, the proportion between the precipitating bath streamfreshly introduced through the nozzles 6 and 28 and the precipitatingbath already used, i. e., precipitating bath which flows from the troughthrough the annular clearance into the insertion, can be changed in anydesired manner through adjustment of the clearance between the wall ofthe trough and the end of the funnel adjacent thereto.

Although only two embodiments of the invention have been describedherein, it is apparent that many modifications thereof may be utilizedand it is not intended to restrict the invention to the embodimentshown. For example, the funnels may be different shapes and means ofmounting the funnels within the trough may be changed in any desiredmanner without departing from the spirit and scope of the invention.Also the positioning of the spinning nozzle may be altered, forinstance, the spinning nozzle might be above the tubular member and thethread be drawn vertically downwardly or at some other suitable angle.In this event, the spinning nozzle might be positioned above the spinbath and the nozzles for precipitating liquid could extend into the spinbath adjacent or within the tubular member. Also, the insertion might beof other shapes suitable for conducting the precipitating liquid incontact with the thread. For example, it might be in the form of an opentrough. Although reference has been made to the introduction of freshprecipitating liquid at the nozzles 6 and 28, it is apparent that thismay include the use of a precipitating liquid which is being reusedafter filtered and otherwise purified.

The above improvement has been described with particular reference tothe cuprammonium process for producing artificial filaments, but it isnot intended to thereby restrict its use to that process, since it mayalso be used to advantage with other processes for producing filamentsof artificial origin; for example, it may be used to advantage in theviscose process.

The terms used in describing the invention have been used in theirdescriptive sense and not as terms of limitation and it is intended thatall equivalents thereof be included within the scope of the appendedclaims.

Having thus described the invention as required by the patent statuteswhat is claimed is:

1. An apparatus of the class described, comprising a spinning nozzle, atrough containing a precipitating solution in which said spinning nozzleis immersed, a tubular element substantially concentric with andsurrounding said spinnerette, and adapted to have the extruded threadspass therethrough, said tubular member having one end adjacent one sideof said trough,

means to vary the distance between the side of said trough and said end.of said tubular member, and means to force fresh precipitating liquidthrough said tubular member and in the direction of travel of thefilaments passing therethrough.

2. A device for manufacturing filaments of artificial origin comprisinga spinneret, a precipitating bath through which the thread from thespinneret is conducted, a tube-like insert arranged within theprecipitating bath and substantially concentrically around the extrudedthread and means for forcing precipitating liquid through saidinsertion.

3. A device as defined in claim 2 in which the means for forcingprecipitating liquid through said insertion comprises a nozzle forintroducing precipitating liquid positioned in the vicinity of thespinneret.

4. A device as defined in claim 2 in which the spinneret is arrangedwithin the tube-like insertion.

5. A device as defined in claim 2 in which the insertion has a conicalshape.

6. A device as defined in claim 2 in which the insertion has a conicalshape, the diameter of the conical insertion decreasing in the directionof travel of the thread.

7. A device as defined in claim 2 in which the insertion has a conicalshape which is enlarged in the direction of travel of the thread.

8. An apparatus for spinning filaments of artificial origin, comprisinga spinning nozzle, a spinning bath, a conduit positioned in saidspinning bath and arranged so that filaments extruded from said spinningnozzle will pass through it, a nozzle directed to force precipitatingliquid through said conduit and to draw precipitating liquid from saidspinning bath into said conduit.

9. An apparatus for spinning filaments of artificial origin, comprisinga spinning nozzle, a spinning bath, a conduit positioned in saidspinning bath and arranged so that filaments extruded from said spinningnozzle will pass through it, a nozzle directed to force precipitat ingliquid through said conduit and to draw precipitating liquid from saidspinning bath into said conduit, and means for adjusting the area of theinlet for precipitating liquid into said conduit.

10. An apparatus of the class described, comprising a spinning nozzlefrom which a thread is extruded, a trough containing a precipitatingsolution in which said spinning nozzle i immersed, a conduit surroundingsaid spinning nozzle longitudinally and adapted to have the extrudedthread pass therethrough, said conduit being substantially submergedinsaid precipitating solution and having one end thereof adjacent oneside of said trough, and means submerged in said precipitating solutionfor forcing fresh precipitating liquid through said conduit and in thedirection of travel of the thread passing therethrough.

11. A device of the class described, comprising a spinnerette, aprecipitating bath through which the thread from the spinnerette isconducted, a conduit arranged substantially within the precipitatingbath and substantially concentrically around the extruded thread, meansfor forcing precipitating liquid through said conduit, said conduithaving one end adjacent one side of said trough, and a take-up rollerpartly submerged in the precipitating solution and pivotally mountedadjacent the other end of said conduit and "adapted to receive thethread issuing from said conduit.

12. A device of the class described, comprising a spinnerette from whicha thread is extruded,

through, an intermediate bottom in said trough positioned below saidconduit, and means ar:-

ranged in said bottom for forcing fresh precipitating liquid throughsaid conduit, said bottom .and said conduit forming a uniform andadjustable annular clearance adapted to control the amount ofprecipitating liquid passing from said trough'into said conduit.

WALTER OSTERMANN.

